Still running a G4 Mac Mini here. I did have 10.5 on it for awhile but the thing strained so hard with running it that I downgraded last week to 10.4. It handles that A LOT better.
I run Mac Office 2008, iPhoto, Comic Life, Photoshop Elements 6, and iTunes all pretty reguarly and hope to get another year to 2 years of life out of this model of Mini.
